The purpose of this study was to investigate the effects of high-intensity interval training (HIT) on peak aerobic power output (PAP) and time trial (TT) performance of Thai amateur cyclists. Twenty-nine male amateur cyclists were randomly allocated to one of two groups, a moderate-intensity continuous training (MICT) group (n = 14) and a HIT group (n = 15). All subjects performed an incremental exercise test to exhaustion and a 30 km TT to determine the PAP, lactate turnpoint (LTP) and endurance performance before (pre-test) and after the six-week training period (post-test). The HIT group completed ten intervals of 2 min at 120% of LTP with 4 min of rest between intervals, 3 times a week. The MICT group completed three sessions per week of 60 min cycling at 60-75% of the maximum heart rate. Both the HIT and MICT groups also completed one session per week of 120-minute continuous training at 60% LTP. The HIT and MIT training programs were six weeks in duration. Both PAP and performance in the 30 km TT were improved post training in the HIT group (p<0.05), but not the MICT group (p>0.05). The present study suggests that a HIT program was more effective at improving PAP and TT performance of Thai amateur cyclists compared to conventional MICT program.
